masseuse formatters

[Duder-onomy]

It would be nice to have a masseuse formatter. There are times when rivets formatters are not adequate. The different between a masseuse formatter and a computed property is that the value is represented differently when being read vs being published.

the interface would look something like this:

someValue : new masseuse.Formatter(read(otherVal), publish(otherVal))

In the following example, the value would be lowercase when being read (in the UI) and uppercase when being published (sent to server)

from a masseuse view model:

inputValue : new masseuse.ProxyProperty('transaction', this.model), //this could be a proxy or a computed
displayedValue : new masseuse.Formatter(
    function(inputValue) {
        return otherValue.toLowerCase();
    },
    function(inputValue) {
        return otherValue.toUpperCase();
    });

---

OR,

The current proxy properties can accept optional 3rd and 4th parameters. These would be a read and publish funciton.

someValue : new masseuse.ProxyProperty('someOtherValue', model, read, write);

function read(someOtherValue) {
   return someOtherValue.toUpperCase();
}

function write(someOtherValue) {
    return someOtherValue.toLowerCase();
}

---

OR,

Make a computed from a proxy:

someValue : new masseuse.ProxyProperty('someOtherValue', model),
valueToDisplay : new masseuse.ComputedProperty(['someValue'], function(someValue) {
    return someValue.toLowerCase();
})

[pajtai]

I like new masseuse.ProxyProperty('someOtherValue', model, read, write);